Review of Black Hole and Grey Hole Attack

Abstract

Black hole and Grey hole attack is most happening attacks in Mesh networks. Mesh networks means nonstatic networks with making loops of networks with the help of active hotspots. In Wireless networks all the communication between the nodes is happening wirelessly and the nodes are so much resource constraint that it is difficult to employ any security solutions of other ad hoc networks. So they are attacked by malicious nodes. In black hole attack the attacker windup all the information and dropped it. In black hole attack, the series of RREQ (route request) and RREP (route reply) follows the smallest way of networking communication. The fault node always transmit RREP message as it receives RREQ, while managing the receivers sequence number. By the help of fault node packets are dropped. Sometimes fault node is authorised and otherwise it is unauthorised. Black hole attack is type of routing attack and can bring harm to whole network. Grey hole attack is the kind of denial of service attack. In this attack, the router which is mesh behave just not well and a subset of packets are forward and handle by receiver but leave by others. The presences of these attackers are hard to detect in wireless networks because over the wireless link the packets are lost due to bad channel quality. This paper deals with the study of analysis of delay occurs by these attack in Wireless Mesh networks and its types and also discuss about previous study by which we get idea about attack occurs in networks and also study various techniques to detect and prevent network from black hole and grey hole attack. Then we discuss about their result by using simulator OPNET.